Can you think of any three-dimensional shape that comprises of exactly two surfaces?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

One day, I thought of ways that can be used for creating a palindrome. So I decided that I will turn into a larger number by adding the reversed digits to the original number and keep doing it till I finally obtained a palindrome.

I am not sure if this process will always result in a palindrome eventually but I was able to produce a four-digit palindrome. Can you guess my starting number?

How far can you walk into the woods?

During which month do people sleep the least?

O_er_t_o_

Complete the missing letters of the given word.

Find the missing number in the sequence below:

What can you catch but never throw?

Intelligence Agency need to break the vault but the problem is that they are not able to break the vault.

On the vault, a text is written as:

31 11 33 33 43 45
21 25
31 24 11 31 51 41

To Break the code Intelligence Agency brings a mathematician named Joseph.
Minutes later he deciphers the code.

Whats the code?

We are a group of eight brothers. We consider the weak, yet we protect the king in every battle. If we move ahead, we never turn back. Who are we?